In a medium pot, combine chocolate, cocoa fat and espresso and melt over low heat, stirring continuously until you have a smooth, shiny mixture. Set aside to cool slightly.
In a bowl, combine eggs and sugar and beat until frothy and light. Fold into chocolate mixture.
In a non-stick mould (or a mould covered with greased aluminum foil), pour some of the mixture, creating a layer at the bottom. Arrange a layer of crackers on top, and then a few thin stripes of marmalade. Repeat, creating thin layers until all ingredients are used.
Place in refrigerator for 2 hours or more before serving. Fold onto serving platter (you might have to dip the mould quickly in hot water). Garnish with wild strawberries.